Biomass pyrolysis furnace

ABSTRACT

A biomass pyrolysis furnace comprises a furnace shell ( 23 ), a furnace container ( 6 ), an exhaust pipe ( 3 ), a smoke pipe ( 18 ), a recovery tower ( 11 ), and an intake pipe ( 7 ), wherein the smoke pipe ( 18 ) is installed on the furnace shell ( 23 ); the furnace container ( 6 ) is installed in the furnace shell ( 23 ); the bottom of the furnace container ( 6 ) and the periphery thereof are provided with a plurality of mesh holes; an exhaust gap ( 24 ) is provided between the furnace container ( 6 ) and the inner wall of the furnace shell ( 23 ); the smoke pipe ( 18 ) is connected to the furnace shell ( 23 ) at one end thereof, and to the recovery tower ( 11 ) at the other end thereof. The furnace shell ( 23 ) is provided, on one side at the upper end, with a flue hole and an intake pipe ( 7 ), and the exhaust pipe ( 3 ) is provided on the opposite side of the furnace shell ( 23 ). The pyrolysis furnace has a short time of biomass pyrolysis, high efficiency, high pyrolysis recovery rate of wood tar, and a simple structure, and therefore it is convenient to operate and maintain.

FIELD OF THE INVENTION

The present invention relates to a device for the biomass fuelpyrolysis, specifically relates to a biomass pyrolysis furnace.

BACKGROUND OF THE INVENTION

The direct-heating pyrolysis furnace is a closed furnace, such as apyrolysis furnace of preventing oxidation (Patent No.:CN200920062938.0), the side walls and the upper side of this pyrolysisfurnace are all non-porous; and the bottom of the said furnace has gapfor discharging water vapor, wood vinegar, wood tar and wood gas and thelike. The biomass is renewable energy source having high moisturecontent. At the beginning of the pyrolysis, the moisture in the biomassis evaporated firstly. After the water changing into vapor, it must passthrough the thick biomass and then enter the smoke flue to bedischarged. Due to blocked by the thick biomass layer, the water vaporcan't pass easily. Thus, the ignition temperature rises continuouslyover time, up to 600° C. and higher, while a large amount of the watervapor, wood vinegar gas, wood tar gas and wood gas and the like aregenerated, resulting in the rise of the pressure in the furnace.The woodgas is in positive proportion to the temperature and pressure, and dueto poor discharging, the ignition temperature in the pyrolysis furnacefurther rises continuously and thus the pressure inside the furnacerises, therefore the pyrolysis in the furnace develops towards thedirection of production of wood gas that is a lot of charcoal and woodtar are converted into the wood gas. The wood gas has low heating valueand is a non-condensable gas, so it has to be evacuated which may causeenvironmental pollution and waste of energy. Even though the ignitiontemperature in the pyrolysis furnace reaches above 600° C., the moisturein the biomass far from the ignition place hasn't been evaporated. Inorder to discharge the gas, the furnace cover is often opened to leverthe biomass with an iron rod. However the quickly burning of the woodtar gas and the wood gas at the top of the furnace brings danger to theoperator, while a lot of flammable gas is discharged, resulting in wasteof energy. Generally, it needs to be levered every four hours. Theresulting amount of charcoal, wood vinegar, wood tar and wood gas isdifferent under different pyrolysis temperatures and different pressure.At atmospheric pressure, under temperature of 300° C., 100 kg of fullydried wood can produce 53 kg of charcoal and only 5.6 cubic meters ofwood gas with heating value of 6594KJ/M3, thus the total heating valueis 36926KJ. Under temperature of 600° C., the yield of charcoal is 28.6kg, and yield of the wood gas is 14.3 cubic meters with heating value of15198KJ/M3, thus the total heating value of wood gas is 217331KJ whichis 5.8 times of that under 300° C., as described on page 32 of((Technology of Wood Waste Recycling & Utilization)) published byChemical Industry Press. Wood tar is inversely proportional to thetemperature and pressure, the higher the temperature is, the less oilproduced, and the higher the pressure is, the less oil produced. Thepyrolysis furnace of length 1 m, width 1 m and height 1 m generallytakes more than eighty hours to evaporate the moisture in the biomass of1 cubic meter and complete the pyrolysis to get the charcoal and oilduring production process. And the water vapor and the wood tar gas aredischarged from the smoke flue to condenser together, so the wood tarcontains a large amount of the water vapor. The yield of the biomasscharcoal and the wood tar is low. As a conclusion after several years'production, 1 ton of woody plant with 25% moisture content can produce0.15 ton of charcoal and 2 kg of wood tar. A large amount of charcoalfuel is converted into the wood gas and wood vinegar, whereas the woodgas is a low-grade fuel and generally is emitted to the air, and thecommodity value of the wood vinegar is low and be seldom used. Thedisadvantages of such device for the pyrolysis of biomass fuel are asfollows: 1. it is heavy labor and unsafe to lever every few hours; 2.long time for the pyrolysis of biomass, low production efficiency andhigh production cost; 3. the yield of the biomass charcoal and wood taris few, a large amount of charcoal fuel is converted into the wood gasand wood vinegar that is a big waste of the raw material.

The recovery tower used for separating the wood tar and the wood gas isarranged vertically in the prior art, such as the recovery towerdescribed in “the environmentally friendly pyrolysis furnace” (PatentNo. CN200920062939.5) is a metal drum. The top and the bottom of themetal drum are closed, and a plurality of hollow tubes are weldedtherebetween, the top end of the metal drum is welded with a coolingpipe, and the lower end of the metal drum is welded with an water pipe.The smoke gas discharged from the big smoke flue passes through thehollow tube in the recovery tower, resulting in the cooling of the woodtar, the wood vinegar and the water, and the wood gas is discharged. Awood tar basin is provided below the recovery tower. In order to ensurethe cooling effect, the height of the recovery tower is usuallyincreased by 20˜50 m. Since the distance between the bottom of the towerand the ground is short, once the path of the recovery tower is blockedby the wood tar, it is hard to clean the path with a tool.

SUMMARY OF THE INVENTION

The technical problem that the present invention aims to solve is toprovide a biomass pyrolysis furnace which is easy to operate, has shorttime of biomass pyrolysis, high efficiency and high pyrolysis recoveryrate of wood tar.

The technical scheme for solving the technical problem is a biomasspyrolysis furnace comprising a furnace shell, a furnace container, asmoke pipe, a recovery tower; the smoke pipe is installed on the furnaceshell, and the furnace container is installed in the furnace shell,characterized in that: the side wall of the furnace container isprovided with a plurality of mesh holes, the bottom of the furnacecontainer either is a plate or is provided with a plurality of meshholes, an exhaust gap is provided between the furnace container and theinner wall of the furnace shell, the smoke pipe is connected to thefurnace shell at one end thereof, and to the recovery tower at the otherend thereof.

Further, the furnace shell is provided with an exhaust pipe communicatedto the furnace container at one side thereof, the furnace shell isprovided with a flue mouth and an intake pipe on one side at the upperend, and the side at which the exhaust pipe is provided is opposite tothe another side at which the intake pipe is provided.

The recovery tower is inclined with an angle a with respect to thehorizontal plane, and 3°≦α≦60°. The inclined arrangement is beneficialfor cleaning the recovery tower.

An induced draft fan is mounted at the outlet of the recovery tower,ensuring the rapid separation of the wood tar, wood vinegar from thecharcoal.

In the present invention, the furnace shell is a closed tank consistingof a shell body and a water-seal cover, the shell body is provided witha water-seal slot at the periphery of the furnace mouth, the lower endof the water-seal cover is positioned within the water-seal slot,ensuring the sealing effect of the furnace shell.

Further, the furnace shell is provided with a cooling basin which maystore cooling liquid at the top thereof. The said cooling basin may befilled with water or other cooling material rapidly after the pyrolysisof the biomass, ensuring the rapid cooling of the furnace shell, andalso avoiding the furnace container to be cooled directly by water whichwill decrease the combustion value of the charcoal.

A liquid-seal valve is provided on the intake pipe or the exhaust pipe.The liquid-seal valve is configured such that it includes theliquid-seal cover, the liquid-seal slot provided on the outer surface ofthe mouth of the intake pipe or the exhaust pipe, and the lower end ofthe liquid-seal cover is positioned within the liquid-seal slot. Theliquid-seal valve can be closed when no air is needed, thus ensuring theabsolute closure of the furnace cavity.

At least one ignition conduit communicated to the furnace container isprovided at the top of furnace shell. A liquid-seal valve is provided atthe mouth of the ignition conduit, and the liquid-seal valve isconfigured such that it includes a liquid-seal cover, a liquid-seal slotprovided on the outer surface of the mouth of the ignition conduit, andthe lower end of the liquid-seal cover is positioned within theliquid-seal slot.

In order to more effectively control the circulation of the smoke gas inthe smoke pipe and exhaust pipe, the smoke pipe is provided with aliquid-seal valve. The liquid-seal valve is configured such that: itincludes an external-valve body, an external-valve cover, aninternal-valve body and an internal-valve cover; the external-valve bodyis provided with a liquid-seal slot at top end thereof, the lower end ofthe external-valve cover is positioned within the liquid-seal slot, theexternal-valve cover and the external-valve body constitute an externalvalve having closed cavity, and the external valve is communicated tothe intake pipe; the internal-valve body is provided with theliquid-seal slot at the outer thereof, the lower end of theinternal-valve cover is positioned within the liquid-seal slot, and theinternal-valve cover and the internal-valve body constitute an internalvalve having a closed cavity; the internal valve positioned in theclosed cavity of the external valve is communicated to the outlet pipe.When need to close the liquid-seal valve, just respectively keep thelower end of the external-valve cover and the lower end of theinternal-valve cover being positioned in corresponding liquid-seal slot,while the closed cavity of the external valve is communicated to theintake pipe instead of the outlet path; when need to open theliquid-seal valve, just keep the lower end of the external-valve coverbeing positioned in the liquid-seal slot and take off the internal-valvecover, resulting in the closed cavity of the external valve is directlycommunicated to the outlet pipe, thereby achieving the unblockedinlet/outlet path.

As further improvement of the present invention, the recovery tower iscommunicated to the wood gas pipe at the outlet thereof, communicated tothe oil collecting basin through a oil pipe at the lower end thereof,communicated to the water tank through the water pipe at the top portionthereof, communicated to the water tank through another water pipeprovided with water circulating pump at the lower portion thereof. Thewater is circularly driven by the water circulating pump in the coolingtower, the cooling effect is more distinct.

Since the furnace container is installed in the furnace shell, thebottom and side walls of the furnace container are provided with aplurality of mesh holes, an exhaust gap is provided between the furnacecontainer and the inner surface of the wall of the furnace shell, thesmoke pipe is connected to the furnace shell at one end thereof, and therecovery tower at the other end thereof.

The pyrolysis process of the biomass fuel is:

Opening the furnace cover (water-seal cover), fully placing the biomassfuel (such as plant straw) into the furnace container, closing thefurnace cover, starting the induced draft fan and igniting the woodblocks, putting them through the ignition conduit of the furnace cover,closing the liquid-seal cover of the ignition conduit, the moisture isextruded from the top and the mesh holes of other five sidewalls of thefurnace container following the rise of the temperature, then bedischarged rapidly through the exhaust pipe through the exhaust gapbetween the furnace container and the furnace shell. By Keeping for 0.5to 1.5 hours when the temperature reaches 80˜150, the moisture in thebiomass cell has been evaporated completely. The biomass has beenpyrolyzed into charcoal, wood tar and wood gas when the temperature ofthe furnace body reaches the setting temperature such as 300° C.following the rise of the temperature and the speeded pyrolysis. Sincethe exhaust is unblocked and the temperature of the pyrolysis portion isabout 300° C., only small amount of the charcoal and the wood tar isconverted into the wood gas. The wood tar and the wood gas flow into therecovery tower (length 20 to 50 m, with a angle a of 15 degree) throughsmoke pipe. The wood tar is cooled and flows out from U-shaped oil pipe,then flows into the oil collecting basin. Collecting the wood gas forbaking the biomass, thus a large amount of biomass is saved. It takesthree to four hours from igniting to 300° C., the speed is increased formore than twenty times compared with more than eighty hours byconventional furnace. It is proved in production that by using a furnaceshell with a square of side length 1.2 m and a height of 1.5 m, andcubic furnace container with size of 1 m*1 m*1 m positioned in thefurnace shell, 1 ton of woody plants with moisture content of 20% canproduce 0.35 ton of charcoal and 0.08 ton of wood tar during about 4hours of pyrolysis time. The pyrolysis furnace according to theinvention has short time of biomass pyrolysis, high efficiency, and highpyrolysis recovery rate of wood tar. And only small quantity of charcoalfuel is converted into the wood gas and the wood vinegar, which meanssmall waste of the raw material. Meanwhile, there is no need to open thefurnace cover and lever the biomass during whole pyrolysis process, sothe operation is safe and labor-saved.

Following is further description of the present invention with referenceto the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural diagram of an embodiment of the presentinvention;

FIG. 2 is a top view of FIG. 1;

FIG. 3 is a structural diagram of an embodiment of the furnace containerof the present invention;

FIG. 4 is a structural diagram of second embodiment of the furnacecontainer of the present invention;

FIG. 5 is a structural diagram of third embodiment of the furnacecontainer of the present invention;

FIG. 6 is a structural diagram of the liquid-seal valve of the presentinvention;

FIG. 7 is a structural diagram of the water-seal cover of the presentinvention;

FIG. 8 is a top view of FIG. 7;

FIG. 9 is a structural diagram of another embodiment of the liquid-sealvalve of the present invention.

In the drawings:

1—thermometer;

2, 8, 19—switch;

3—exhaust pipe;

4—U-shaped water-seal slot;

5—water-seal cover;

6—furnace container;

7—intake pipe;

9—wood gas pipe;

10—induced draft fan;

11—recovery tower;

12, 15—water pipe;

13—water tank;

14—water pump;

16—U -type oil pipe;

17—oil collecting basin;

18—smoke pipe;

20—thermometer;

21—angle iron;

22—metal mesh;

23—furnace shell;

24—exhaust gap;

25—external-valve cover;

26—external-valve body;

27—internal-valve cover;

28—internal-valve body;

29, 30, 33—liquid-seal slot;

31—cooling basin;

32—liquid-seal cover;

34—ignition conduit.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A biomass pyrolysis furnace as shown in FIG. 1 and FIG. 2, comprises afurnace shell 23, a furnace container 6, an exhaust pipe 3, an intakepipe 7, a smoke pipe 18, a recovery tower 11. The smoke pipe 18 isinstalled on the furnace shell 23, and the furnace container 6 isinstalled in the furnace shell 23. The bottom of the furnace container 6and periphery thereof are provided with a plurality of mesh holes. Anexhaust gap 24 which may be used for discharge of vapor is providedbetween the furnace container 6 and the inner surface of the wall of thefurnace shell 23. The smoke pipe 18 is connected to the furnace shell 23at one end thereof, and to the recovery tower 11 at the other endthereof.

The pyrolysis furnace shell 23 may be a six-side closed tank comprisinga shell body and a water-seal cover 5. At its periphery, the furnacemouth of the shell body is provided with an U-shaped water-seal slot 4which is full of water, as shown in FIGS. 7 and 8. The water-seal cover5 is a cover flanging down at periphery, and the periphery is embeddedin the U-shaped water-seal slot 4, thereby ensuring the sealing effectof the furnace shell. The furnace shell 23 is provided, on one side atthe upper end, with a smoke pipe 18 and an intake pipe 7, and theexhaust pipe 3 is provided on the opposite side of the furnace shell 23.The smoke pipe 18 is provided with a switch 19 and a thermometer 20, theintake pipe 7 is provided with a switch 8, and the exhaust pipe 3 isprovided with a thermometer 1 and a switch 2. The furnace shell 23 isprovided, at the top portion, with four ignition conduits 34communicated to the furnace container, the ignition conduit 34 isprovided with a liquid-seal valve at the mouth thereof. The liquid-sealvalve structurally includes a liquid-seal cover 32, which is a coverflanging down at periphery, the liquid-seal slot 33 is provided on theouter surface of the wall of the ignition conduit, and the lower end ofthe liquid-seal cover 32 is positioned in the liquid-seal slot 33.Opening the liquid-seal cover 32 when igniting is needed, and theliquid-seal cover 32 is closed with its lower end embedded in theliquid-seal slot 33 after igniting in the ignition conduit, therebyclosing the liquid-seal valve to prevent leakage of smoke gas.

As shown in FIG. 6, the switch 2, 8, 19 preferred are the good-closedliquid-seal valve. The liquid-seal valve is configured such that itincludes an external-valve body 26, an external-valve cover 25, aninternal-valve body 28 and an internal-valve cover 27, theexternal-valve cover 25 and the internal-valve cover 27 both are coversflanging down at periphery, the external-valve body 26 is provided, attop portion thereof, with a liquid-seal slot, the lower end of theexternal-valve cover 25 is positioned in the liquid-seal slot 29, andthe external-valve cover 25 and the external-valve body 26 constitute anexternal valve with a closed cavity which is communicated to the intakepipe; as well as the internal-valve body 28 is provided, at the exteriorthereof, with the liquid-seal slot in which the lower end of theinternal-valve cover 27 is positioned, the internal-valve cover 27 andthe internal-valve body 28 constitute an internal valve with closedcavity; and the internal valve positioned in the closed cavity of theexternal valve is communicated to the outlet pipe. When the liquid-sealvalve is needed to be closed, just keep the lower end of theexternal-valve cover 25 and the lower end of the internal-valve cover 27being respectively positioned in corresponding liquid-seal slot, Whilethe closed cavity of the external valve is communicated to the intakepipe instead of the outlet path; when the liquid-seal valve is needed tobe open, just keep the lower end of the external-valve cover 25 beingpositioned in the liquid-seal slot and take off the internal-valve cover27, resulting in the closed cavity of the external valve is directlycommunicated to the outlet pipe, thereby achieving the unblockedinlet/outlet path.

Certainly, the switch 2, 8 also may be in following structure. As shownin FIG. 9, the pipe is provided, at the mouth thereof, with aliquid-seal slot 33 and a liquid-seal cover 32 which is a cover flangingdown at periphery. Sealing is realized when the lower end of theliquid-seal cover is positioned in the liquid-seal slot 33, and if theliquid-seal valve is needed to be open, just take off the liquid-sealcover 32.

Furthermore, the furnace shell 23 is provided, at top end thereof, witha cooling basin 31 for storage of cooling water, the cooling basin 31may be a basin with opening at the top, which is formed by the furnaceshell 23 and four steel plates welded on the top surface of the furnaceshell 23, the cooling basin 31 may be filled with water rapidly afterthe pyrolysis of the biomass, ensuring the rapid cooling of the furnaceshell 23, which is faster than natural air cooling, and can also avoidthe furnace container 6 to be cooled directly by water which willdecrease the combustion value of the charcoal.

The recovery tower 11 is inclined with a angle a with respect to thehorizontal plane, and 3°≦α≦60°. There is a distance between the bottomof the tower and the ground, which is good for using a tool to clear thepath whenever the path in the recovery tower is blocked by the wood tar.

The furnace container 6 is positioned in the furnace shell 23, as shownin FIG. 3, the bottom and the side wall of the furnace container 6 areall formed by metal mesh 22, and the mouth of the furnace container 6 isopened. Each sidewall is welded by an angle irons 21, and the metal mesh22 is welded on the angle iron 21. The bottom of the furnace container 6may be made of steel plate if size of the biomass granule is relativesmaller. Certainly, the furnace container 6 may also be in thestructures shown in FIGS. 4 and 5.

The switch 19 is connected to the recovery tower 11 which is a metaldrum and provided with a flange cover at the two ends respectively, Twomental plates are welded respectively at the positions about 50 cm fromthe mouths of the flanges. Each of the metal plates is provided with aplurality of holes, and a plurality of metal hollow tubes are weldedbetween the plurality of holes on one metal plate and the plurality ofholes on the other plate. The metal drum is welded with a water pipe 12at the upper end thereof, and welded to a water pipe 15 at the lowerend. One end of the water pipe 12 is inserted into a water tank 13, andthe water tank 13 is connected to the water pipe 15 through a water pump14. The upper end of the recovery tower 11 is connected to the induceddraft fan 10 which is connected to the wood gas pipe 9 at the windoutlet. The recovery tower 11 is provided with an U-shaped oil pipe 16at the lower end, and an oil collecting basin 17 is provided below theU-shaped oil pipe 16. When the recovery tower 11 is blocked by the woodtar, the wood tar may be removed by opening the flange cover at thelower end of the recovery tower 11 and inserting a steel fiber into themetal hollow tubes.

Some dozens of smoke pipes 18 for the pyrolysis furnace can beparallelly connected with each other and then connected to the recoverytower 11.

The pyrolysis process of the biomass fuel is as follows:

Opening the water-seal cover 5, fully placing the biomass fuel (such asplant straw) in the furnace container 6, closing the water-seal cover 5,igniting at least one of wood blocks and putting them into the furnacecontainer 6 from the ignition conduit 34;

Closing the liquid-seal cover 32 of the ignition conduit 34, filling theU-shaped water-seal slot 4 with water, then opening switch 2, at thistime the moisture is extruded from the top and the mesh holes of otherfive sidewalls of the furnace container, and then is discharged throughthe exhaust pipe 3;

Regulating the switch 8 to control the volume of incoming air to preventextinguishment and extra air oxidation;

Keeping for 0.5 to 1.5 hours when the temperature of the thermometer 1reaches 80˜150 following the rise of the temperature, then closing theswitch 2 and opening the switch 19, starting the induced draft fan 10,starting the water pump 14, regulating the switch 8 to control thevolume of incoming air to prevent extra air oxidation, the wood tar andthe wood gas flow into the recovery tower 11 from the smoke pipe 18, thecold water flows into the recovery tower 11 through water pipe 15, andflows out from the water pipe 12 of the recovery tower 11.

The wood tar is cooled and flows out from U-shaped oil pipe 16, thenflows into the oil collecting basin 17 for storage. A large amount ofbiomass charcoal, wood tar, wood vinegar and a small quantity of woodgas and the like have been pyrolyzed from the biomass when the readingof the thermometer 20 reaches about 300° C.

The comparison between the pyrolysis of biomass fuel in the pyrolysisfurnace according to the invention and that in the conventionalpyrolysis furnace is shown in the following table.

1 ton of wooden biomass with 25% moisture content, after pyrolysis,comparison between the yields of the charcoal and wood tar in two kindsof pyrolysis furnaces Product Yield of charcoal Yield of wood tarConventional 0.15 ton 0.02 ton furnace This pyrolysis 0.35 ton 0.08 tonfurnace

As can be seen from the table, after the pyrolysis of one ton of biomassfuel, the yields of the charcoal and the wood tar in this pyrolysisfurnace are greatly higher than those in the conventional pyrolysisfurnace.

Although the detailed content have been illustrated with the foregoingembodiments, it should be understood that these embodiments are onlyused for more clearly explaining the present invention, and not intendedto limit the range of the present invention. After reading the presentinvention, various equivalent modifications can be made by those skilledin the art and should fall in the scope of the invention defined by theappended claims of this application.

What is claimed is:
 1. A biomass pyrolysis furnace, comprising a furnaceshell, a furnace container, a smoke pipe, and a recovery tower; wherein,the smoke pipe is installed on the furnace shell, and the furnacecontainer is installed in the furnace shell, characterized in that, aside wall of the furnace container is provided with a plurality of meshholes, a bottom of the furnace container either is a plate or isprovided with a plurality of mesh holes, an exhaust gap is providedbetween the furnace container and an inner surface of the side wall ofthe furnace shell, and the smoke pipe is connected to the furnace shellat one end thereof and to the recovery tower at the other end thereof.2. The biomass pyrolysis furnace according to claim 1, characterized inthat, the furnace shell is provided with an exhaust pipe communicated tothe furnace container at one side thereof, the furnace shell is providedwith a flue mouth and an intake pipe at an upper end on another sidethereof, and the side at which the exhaust pipe is provided is oppositeto the another side at which the intake pipe is provided.
 3. The biomasspyrolysis furnace according to claim 1, characterized in that therecovery tower is inclined with an angle a with respect to thehorizontal plane, and 3°≦α≦60°.
 4. The biomass pyrolysis furnaceaccording to claim 1, characterized in that an induced draft fan ismounted on the recovery tower at an outlet portion thereof
 5. Thebiomass pyrolysis furnace according to claim 1, characterized in that,the furnace shell is a closed tank consisting of a shell body and awater-seal cover, the shell body is provided with a water-seal slot at aperiphery of a furnace mouth, the lower end of the water-seal cover ispositioned within the water-seal slot.
 6. The biomass pyrolysis furnaceaccording to claim 1, characterized in that, the furnace shell isprovided with a cooling basin configured to store cooling liquid at atop end thereof.
 7. The biomass pyrolysis furnace according to of claim1, characterized in that, the smoke pipe is provided with a liquid-sealvalve, the liquid-seal valve is configured such that it includes anexternal-valve body, an external-valve cover, an internal-valve body andan internal-valve cover, the external-valve body is provided with aliquid-seal slot at a top end thereof, a lower end of the external-valvecover is positioned within the liquid-seal slot, the external-valvecover and the external-valve body constitute an external valve having aclosed cavity, and the external valve is communicated to an intake pipe;the internal-valve body is provided with a second liquid-seal slot atthe outer surface thereof, a lower end of the internal-valve cover ispositioned within the second liquid-seal slot, and the internal-valvecover and the internal-valve body constitute an internal valve having aclosed cavity; wherein the internal valve positioned in the closedcavity of the external valve is communicated to an outlet pipe.
 8. Thebiomass pyrolysis furnace according to claim 2, characterized in that,the intake pipe or exhaust pipe is provided with a liquid-seal valve,the liquid-seal valve is configured such that it includes a liquid-sealcover and a liquid-seal slot provided at an outer surface of a mouth ofthe intake pipe or the exhaust pipe, and a lower end of the liquid-sealcover is positioned within the liquid-seal slot.
 9. The biomasspyrolysis furnace according to claim 1, characterized in that, at leastone ignition conduit communicated to the furnace container is providedat a top end of furnace shell, a liquid-seal valve is provided at amouth of the ignition conduit, the liquid-seal valve is configured suchthat it includes a liquid-seal cover, a liquid-seal slot is provided onan outer surface of the mouth of the ignition conduit, and a lower endof the liquid-seal cover is positioned within the liquid-seal slot. 10.The biomass pyrolysis furnace according to claim 1, characterized inthat, the recovery tower is: communicated to a wood gas pipe at anoutlet thereof, communicated to an oil collecting basin through an oilpipe at a lower end thereof, communicated to a water tank through awater pipe at a top portion thereof, and communicated to the water tankthrough another water pipe provided with a water circulating pump at alower portion thereof.
 11. The biomass pyrolysis furnace according toclaim 5, characterized in that, the furnace shell is provided with acooling basin configured to store cooling liquid.
 12. The biomasspyrolysis furnace according to claim 2, characterized in that, the smokepipe is provided with a liquid-seal valve, the liquid-seal valve isconfigured such that it includes an external-valve body, anexternal-valve cover, an internal-valve body and an internal-valvecover, the external-valve body is provided with a liquid-seal slot at atop end thereof, a lower end of the external-valve cover is positionedwithin the liquid-seal slot, the external-valve cover and theexternal-valve body constitute an external valve having a closed cavity,and the external valve is communicated to the intake pipe; theinternal-valve body is provided with a second liquid-seal slot at theouter surface thereof, a lower end of the internal-valve cover ispositioned within the second liquid-seal slot, and the internal-valvecover and the internal-valve body constitute an internal valve having aclosed cavity; wherein the internal valve positioned in the closedcavity of the external valve is communicated to an outlet pipe.
 13. Thebiomass pyrolysis furnace according to claim 3, characterized in that,the smoke pipe is provided with a liquid-seal valve, the liquid-sealvalve is configured such that it includes an external-valve body, anexternal-valve cover, an internal-valve body and an internal-valvecover, the external-valve body is provided with a liquid-seal slot at atop end thereof, a lower end of the external-valve cover is positionedwithin the liquid-seal slot, the external-valve cover and theexternal-valve body constitute an external valve having a closed cavity,and the external valve is communicated to an intake pipe; theinternal-valve body is provided with a second liquid-seal slot at theouter surface thereof, a lower end of the internal-valve cover ispositioned within the second liquid-seal slot, and the internal-valvecover and the internal-valve body constitute an internal valve having aclosed cavity; wherein the internal valve positioned in the closedcavity of the external valve is communicated to an outlet pipe.
 14. Thebiomass pyrolysis furnace according to claim 4, characterized in that,the smoke pipe is provided with a liquid-seal valve, the liquid-sealvalve is configured such that it includes an external-valve body, anexternal-valve cover, an internal-valve body and an internal-valvecover, the external-valve body is provided with a liquid-seal slot at atop end thereof, a lower end of the external-valve cover is positionedwithin the liquid-seal slot, the external-valve cover and theexternal-valve body constitute an external valve having a closed cavity,and the external valve is communicated to an intake pipe; theinternal-valve body is provided with a second liquid-seal slot at theouter surface thereof, a lower end of the internal-valve cover ispositioned within the second liquid-seal slot, and the internal-valvecover and the internal-valve body constitute an internal valve having aclosed cavity; wherein the internal valve positioned in the closedcavity of the external valve is communicated to an outlet pipe.
 15. Thebiomass pyrolysis furnace according to claim 5, characterized in that,the smoke pipe is provided with a liquid-seal valve, the liquid-sealvalve is configured such that it includes an external-valve body, anexternal-valve cover, an internal-valve body and an internal-valvecover, the external-valve body is provided with a liquid-seal slot at atop end thereof, a lower end of the external-valve cover is positionedwithin the liquid-seal slot, the external-valve cover and theexternal-valve body constitute an external valve having a closed cavity,and the external valve is communicated to an intake pipe; theinternal-valve body is provided with a second liquid-seal slot at theouter surface thereof, a lower end of the internal-valve cover ispositioned within the second liquid-seal slot, and the internal-valvecover and the internal-valve body constitute an internal valve having aclosed cavity; wherein the internal valve positioned in the closedcavity of the external valve is communicated to an outlet pipe.
 16. Thebiomass pyrolysis furnace according to claim 2, characterized in that,at least one ignition conduit communicated to the furnace container isprovided at a top end of furnace shell, a liquid-seal valve is providedat a mouth of the ignition conduit, the liquid-seal valve is configuredsuch that it includes a liquid-seal cover, a liquid-seal slot isprovided on an outer surface of the mouth of the ignition conduit, and alower end of the liquid-seal cover is positioned within the liquid-sealslot.
 17. The biomass pyrolysis furnace according to claim 3,characterized in that, at least one ignition conduit communicated to thefurnace container is provided at a top end of furnace shell, aliquid-seal valve is provided at a mouth of the ignition conduit, theliquid-seal valve is configured such that it includes a liquid-sealcover, a liquid-seal slot is provided on an outer surface of the mouthof the ignition conduit, and a lower end of the liquid-seal cover ispositioned within the liquid-seal slot.
 18. The biomass pyrolysisfurnace according to claim 4, characterized in that, at least oneignition conduit communicated to the furnace container is provided at atop end of furnace shell, a liquid-seal valve is provided at a mouth ofthe ignition conduit, the liquid-seal valve is configured such that itincludes a liquid-seal cover, a liquid-seal slot is provided on an outersurface of the mouth of the ignition conduit, and a lower end of theliquid-seal cover is positioned within the liquid-seal slot.
 19. Thebiomass pyrolysis furnace according to claim 5, characterized in that,at least one ignition conduit communicated to the furnace container isprovided at a top end of furnace shell, a liquid-seal valve is providedat a mouth of the ignition conduit, the liquid-seal valve is configuredsuch that it includes a liquid-seal cover, a liquid-seal slot isprovided on an outer surface of the mouth of the ignition conduit, and alower end of the liquid-seal cover is positioned within the liquid-sealslot.
 20. The biomass pyrolysis furnace according to claim 2,characterized in that, the recovery tower is: communicated to a wood gaspipe at an outlet thereof, communicated to an oil collecting basinthrough an oil pipe at a lower end thereof, communicated to a water tankthrough a water pipe at a top portion thereof, and communicated to thewater tank through another water pipe provided with a water circulatingpump at a lower portion thereof.
 21. The biomass pyrolysis furnaceaccording to claim 3, characterized in that, the recovery tower is:communicated to a wood gas pipe at an outlet thereof, communicated to anoil collecting basin through an oil pipe at a lower end thereof,communicated to a water tank through a water pipe at a top portionthereof, and communicated to the water tank through another water pipeprovided with a water circulating pump at a lower portion thereof. 22.The biomass pyrolysis furnace according to claim 4, characterized inthat, the recovery tower is: communicated to a wood gas pipe at anoutlet thereof, communicated to an oil collecting basin through an oilpipe at a lower end thereof, communicated to a water tank through awater pipe at a top portion thereof, and communicated to the water tankthrough another water pipe provided with a water circulating pump at alower portion thereof.
 23. The biomass pyrolysis furnace according toclaim 5, characterized in that, the recovery tower is: communicated to awood gas pipe at an outlet thereof, communicated to an oil collectingbasin through an oil pipe at a lower end thereof, communicated to awater tank through a water pipe at a top portion thereof, andcommunicated to the water tank through another water pipe provided witha water circulating pump at a lower portion thereof.